Refinery::Image delete in overview => Error on association

[mattherick]

I have an own refinery extension, so far so good and everything works.
I have a Project which has a logo => association to Refinery::Image

    module Refinery
      module Projects
        class Project < Refinery::Core::BaseModel
          self.table_name = 'refinery_projects'
          belongs_to :logo, :class_name => '::Refinery::Image'
          attr_accessible :logo_id
          validates :logo_id, :presence => true
        end
      end
    end

In the Refinery::Images overview I can edit, update and destroy the image, so far so good.

But no my problem is, that I have validates :presence => true on my project logo. And If I have an image_tag in my views like:

<%= image_tag @project.logo.url %> 

And the image was destroyed on localhost:3000/refinery/images I get an exception

undefined method `url' for nil:NilClass

because of the missing image of the association.

Is this a bug or a feature?

Of course I could fix the view exception like:

<%= image_tag @project.logo.url if @project.logo %> 

but that is annoying, because of the presence validation.

[parndt]

That makes sense.. if you delete an image it's going to be nil?

[mattherick]

Yes it makes sense and also not :-). Is there a workaround to fix that?

[parndt]

The workaround you suggested, yes.

[mattherick]

Why not fix this within refinery? For example, if an image is associated to something, it is not deletable? A before filter for example "This image is associated to.., not deletable".. ?

[parndt]

How does the image know what it's associated with?

[mattherick]

Yes that's the problem. Maybe it could be fixed within the refinery-images gem. For own extensions everybody must fixed it individually...hmm.

[parndt]

Currently other models own the foreign key relationship with images and we'd have to flip that around the other way to implement what you're after.
So, an image would have to has_many :records_from_other_models and it'd need to be polymorphic.